Bitshifts and "And" vs Floor-division and Modular

[Dave Angel]

On 09/07/2012 12:59 PM, rusi wrote:
> On Sep 7, 9:32 am, Paul Rubin <no.em... at nospam.invalid> wrote:
>> rusi <rustompm... at gmail.com> writes:
>>> On an 8086/8088 a MUL (multiply) instruction was of the order of 100
>>> clocks ...  On most modern processors (after the pentium) the
>>> difference has mostly vanished.  I cant find a good data sheet to
>>> quote though
>> See http://www.agner.org/optimize/:
> Hey Thanks! Seems like a nice resource!  How on earth does he come up
> with the data though, when Intel does not publish it?

As he says on the home page, he measured the data himself.  Unclear how
repeatable such data may be, either due to environment or to multiple
versions of the processor, and from two vendors.

-- 

DaveA